FR2549663A1 - Method and device for encoding and decoding broadband transmission - Google Patents

Method and device for encoding and decoding broadband transmission Download PDF

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Publication number
FR2549663A1
FR2549663A1 FR8312043A FR8312043A FR2549663A1 FR 2549663 A1 FR2549663 A1 FR 2549663A1 FR 8312043 A FR8312043 A FR 8312043A FR 8312043 A FR8312043 A FR 8312043A FR 2549663 A1 FR2549663 A1 FR 2549663A1
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FR
France
Prior art keywords
code
elementary
generators
codes
signal
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
FR8312043A
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French (fr)
Inventor
Michel Jacques Robert Nicolas
Bruno Roger Sebilet
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Safran Aircraft Engines SAS
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Safran Aircraft Engines SAS
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Publication date
Application filed by Safran Aircraft Engines SAS filed Critical Safran Aircraft Engines SAS
Priority to FR8312043A priority Critical patent/FR2549663A1/en
Publication of FR2549663A1 publication Critical patent/FR2549663A1/en
Application status is Withdrawn legal-status Critical

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J13/00Code division multiplex systems
    • H04J13/10Code generation
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B1/7073Synchronisation aspects

Abstract

METHOD FOR CODING RADIO EMISSIONS BY SPECTRUM SPREADING USING A PSEUDOALEATORY CODE FOLLOWING THE INVENTION, THE USEFUL SIGNAL IS PHASE MODULE USING A MODULATOR 11 OP CONTROLLED BY A PSEUDOALEATOIC SEQUENCE FORMED BY THE COMBINATION BY MAJORITY LOGIC OF AN ENOUGH NUMBER OF ELEMENTARY CODES A, B, C CONSTITUTED BY SEQUENCES PSEUDOALEATORY BINARS OF DIFFERENT LENGTHS. ON RECEPTION, THE SETTING OF THE CODE IS CARRIED OUT BY CORRELATING EACH OF THE BASIC CODES A, B, C WITH THE SIGNAL RECEIVED SC. </ P> <P> THE INVENTION IS USED FOR RADIO TRANSMISSIONS FOR WHICH WE WANT TO AVOID INTERFERENCE AND DECRYPTAGES. </ P>

Description

Method and device for coding and

  decoding a broadcast to the band.

  The present invention relates to a method for coding and decoding broad band erasm, a method of the type in which a useful signal to be transmitted is modulated in phase by means of an OI modulator controlled by a code consisting of a sequence of binary values and the signal transmitted and received is demodulated in phase by means of a demodulator O f command by the same code, the code used in reception being

  compared to the one used in transmission by correlation with the received signal.

  It is well known, in order to avoid interference and decryption of an emission, to carry out coding by a wide spectrum spread. In the method of the type indicated above, spectrum spreading is carried out in accordance with FIG. modulating, using an ON modulator, the useful signal by a code whose spectrum is much greater In reception, the code is corrected by correlation with the received signal; for this purpose, delaying means are used to progressively shift the code relative to the received signal until the detection

peak correlation.

  It is obvious that, in order to be effective, the code must be long. However, the longer the code used, the more the calibration operation on reception.

  takes time and quickly becomes prohibitive.

  The present invention aims to provide a method of the aforementioned type which retains the advantages related to

  o the use of a long code while allowing a very fast setting of the code on the receiving side.

  This object is achieved by virtue of the fact that, in accordance with the invention, the code used is a compound code formed by the majority logic combination of an odd number of elementary codes forms of binary sequences

  pseudo-random of different lengths, and the calibration of the code in reception is achieved by correlation of each of the elementary codes with the received signal.

  The use of elementary codes of different lengths, and preferably first ones between them, makes it possible to preserve for coding the advantages of the long codes, that is to say the protection against decryption, the uniform spreading of the power in the

  frequency domain used and a high processing gain, thus a good protection against interference.

  To these advantages is added the possibility of performing the calibration operation in reception in a very short time since it relates to the elementary codes According to whether the correlations thereof with the received signal are made in parallel or successively, the duration of the calibration operation is that required to calibrate the longest elementary code or the sum of those

  necessary for the calibration of different elementary codes.

  Even in the latter case, the duration of the calibration operation is negligible compared to that which would be

  necessary to correlate with the signal received a code of the same length as the code compound.

  The present invention also relates to a device enabling the implementation of the method 25 in a communication system comprising an emitter

and at least one receiver.

  This object is achieved by means of a device of the type comprising, on the transmitter side: a phase modulator O 5 receiving a useful signal to be transmitted and generating a coded signal and a first code generator formed of a sequence of binary values and controlling the phase modulator; and on the side of the or each receiver: a phase demodulator OO receiving the coded signal and reproducing the decoded useful signal, a code generator generating the same code as that used on the transmitter side and controlling the phase demodulator, and correlating means receiving the coded signal and connected to the second decode generator to calibrate the code generator used in a receiver with respect to that used in the transmitter, in which device according to the invention: each code generator comprises several odd-numbered elementary generators intended to generate elementary codes formed of pseudo-random bit sequences of different lengths, a control circuit of the elementary generators and a combination circuit connected to the outputs of the elementary generators and delivering a code formed by the combination by majority logic of the elementary codes, the m Correlation means receive, on the one hand, the coded signal and, on the other hand, each of the codes

  elements generated by the elementary generators.

  of the receiver, and the control circuit of the elementary generators of the receiver comprises setting means

  acting in response to signals provided by the correlation means to wedge each of these elementary generators independently of the others.

  According to a first embodiment of the device according to the invention, the correlation means comprise: a single correlator circuit and means

  switching devices which are arranged between the elementary generators of the receiver and this correlator circuit and which are controlled by signals supplied by the control circuit.

  According to a second embodiment of the device according to the invention, the correlation means comprise several correlator circuits in number equal to that of the elementary generators and each receiving, on the one hand, the coded signal and, on the other hand, part, a

particular elementary code.

  Other features and advantages of the method and device in accordance with the invention will be apparent from reading the description given below,

  As an indication but without limitation, reference to the accompanying drawings in which: Figure 1 is a diagram showing a first embodiment of a device according to the invention, and

  Figure 2 is a diagram of the receiver of a second embodiment of a device according to the invention.

  The communication system referred to in FIG. 1 comprises a transmitter 10 and at least one receiver 20, the transmission and reception of the signals being ensured, for example by radio, by means of antennas (not shown). receives a useful signal S to be coded and transmitted The coding is carried out in a manner known per se, by means of a phase modulator O which delivers the coded signal SC and which is controlled by a code formed by a sequence of bits, the phase of the useful signal being inverted or not depending on the value of each bit that occurs and the rate of presentation

of these bits.

  In accordance with the invention, the code applied to the phase modulator 11 is a composite code formed by the majority logic combination of an even number of elementary codes. In the example illustrated, the elementary codes are three in number but all

  odd number greater than three could be used.

  The various codes a, b, c are produced by code generators 12, 13, 14 and are formed by sequences of pseudo-random bits. The numbers na, nb, nc of bits forming the codes a, b, c are The combination by majority logic is performed by a logic circuit 15 which receives the codes a, b, c provided by the generators 12, 13 and 14 and which carries out the logic function ab + bc + ac. generators 12, 13, 14 are synchronously controlled by a clock 16 which delivers a signal H formed by pulses whose frequency F determines the rate of movement of the successive bits 10 of each code; the generators 12, 13, 14 comprise, for example, shift registers looped on themselves and controlled by the signal H. For each group of three bits which occur simultaneously, the logic circuit 15 supplies a bit whose value (O or 1) 15 is equal to the majority value in this group Thus, at the output of the circuit 15, a composite code lm (a, b, c) is obtained whose successive bits occur at the frequency F and whose length is equal to the least common multiple of na, nb and nc, that is to say

  to na x nb x nc if these numbers are prime between them.

  It can be considered that the gain provided by the coding method according to the invention is comparable to the ratio

  from the smallest common multiple to the sum of the numbers na, nb and nc; this gain is therefore maximal when these numbers are prime between them.

  The coded signal SC is demodulated in the receiver 20 by passing through a phase demodulator O1 21 controlled by a code identical to that used in FIG.

  The transmitter for recovering the useful signal S in output of the demodulator 21 - The synchronization of the code used in the receiver with that used in the transmitter is performed by correlation with the received signal.

  The code supplied to the demodulator 21 is generated by means of a logic circuit 25 identical to the circuit 15, by the majority logic combination of the three codes a, b, c provided by generators 22, 23, 24 identical to the generators 12. , i 3, 14 and controlled by signals Ha, Hb, Hc These are delivered by respective clocks 32, 33, 34 of a control circuit 26. The synchronization of the code of the receiver 21 with that of the The transmitter is effected by correlating each code a, b, c with the coded signal SC. In the embodiment of FIG. 1, the correlations of the codes a, b, c with the signal SC are carried out successively by means of a signal. same correlation circuit 27 of which one input receives the signal SC and whose other input is connected to the generators 22, 23, 24 via respective switches 28a, 28b, 28c In response to the detection of a peak of correlation, the circuit 27 provides a signal on its connected output three inputs of the circuit 26 through respective switches 29a, 29b, 29c Each code generator 22, 23, 24 is synchronized to the received code 20 by controlling the delay with which the local code is transmitted relative to to the received code This is achieved by accelerating or slowing down the clock associated with the code generator, the setting thereof being achieved by controlling the local code and the code received For this purpose, each clock 32, 33, 34 delivers the signals Ha, Hb and Hc with a variable frequency under the control of signals S Ha, S Hb and S Hc produced by frequency control circuits 35, 36 and 37 These have

  inputs respectively connected to switches 29a, 29b and 29c.

  The setting of a generator, for example 22, is performed as follows Switches 28a and 29a are closed and the other switches 28b, 28c, 29b and 29c are open, the different pairs of switches 28a -29 a, 28 b 29 b and 28 c 29 c being ordered by

49663

7.

  AC, DC, DC signals produced by a sequencer circuit 38.

  The frequency of the clock 32 is varied by means of the circuit 35 until detection by this circuit of a signal fa coming from the circuit 27 and indicating the presence of a correlation peak, this detection causing the locking of the Then the switches 28a, 29a are open and the switches 28b, 29b are closed to perform in the same manner.

  setting the clock 33 and the generator 23 in response to a signal pb indicating a new correlation peak.

  Finally, the switches 28b, 29b are open and the

  switches 28c, 29c are closed to calibrate the clock 34 and the generator 24-in response to a pc signal indicating a new correlation peak.

  The calibration of the generators 22, 23, 24 being then completed, the actual decoding can begin. It will be noted that the sequencer 38 produces signals applied to the circuits 35, 36, 37 for triggering the stall phases of the generators 22, 23, 24. response to an external command and to signals received from circuits 36, 37, and

  indicating that the generators 22 and 23 have been keyed.

  FIG. 2 illustrates another embodiment of the receiver, the elements identical to those illustrated in FIG. 1 bearing the same references. In this other embodiment, the setting of the generators 22, 23, 24 is performed in parallel instead of sequentially for this purpose are provided three correlation circuits 27a, 27b, 27c which receive the signal SC on a first input and whose second inputs

  are respectively connected to the generators 22, 23, 24.

  A control circuit 26 'receives the signals pa, lb, and c of the correlation circuits 27a, 27b, 27c and generates the timing signals Ha, Hb, Hc in response thereto.

generators 22, 23, 24.

  As already indicated, the invention is particularly

  It is advantageous in that it combines the advantages of a long code with those of a fast calibration of the code in reception. In order to maintain correlation peaks of sufficient amplitude to enable reliable detection, it is desirable to However, this is not an inconvenient limitation since codes composed of several millions or tens of millions of bits can be obtained from three short elementary codes of a few hundred or so. thousands of bits requiring only a limited time for receiving timing.

Claims (7)

  1 method for encoding and decoding a broadband transmission, wherein a useful signal to be transmitted is phase modulated by means of a modulator O1 controlled by a code formed of a sequence of binary values and the transmitted and received signal is demodulated in phase by means of a demodulator O IL controlled by the same code, the code used in reception being calibrated with respect to that used in the transmission by correlation with the received signal, characterized in that that the code used is a composite code formed by the combination by majority logic of an odd number of elementary codes formed of pseudo-random bit sequences of different lengths, and the coding of the code in reception is carried out by correlation of each of the elementary codes. with the received signal.
 2 Method according to claim 1, characterized in that the number of bits of the elementary codes 20 are first between them
  Process according to either of Claims 1 and 2, characterized in that the correlations of the
  elementary codes with the received signal are realized successively.
  4 Process according to any one of claims 1 and 2, characterized in that the correlations of
  elementary codes with the received signal are realized
in parallel.
  Device for coding and decoding a
  broadband transmission in a communication system comprising a transmitter and at least one receiver, a device comprising, on the transmitter side: a phase modulator OO receiving a signal useful for transmitting and generating a coded signal and a first code generator formed of a sequence of binary values and
  mandating the phase modulator; and on the side of the or each receiver: an ON phase demodulator receiving the coded signal and restoring the decoded useful signal, a second code generator generating the same code as that used on the transmitter and controlling the phase demodulator , and correlation means receiving the coded signal and connected to the second code generator for wedging the code generator used in a receiver with respect to that used in the transmitter, characterized in that: each code generator comprises: a plurality of odd-numbered elementary generators (12-14, 22-24) for generating elementary codes (a, b, c) pseudo-random bit pattern forms of different lengths, a control circuit (16, 26;
 26 ') of the elementary generators and a combination circuit (15, 25) connected to the outputs of the elementary generators and delivering a code formed by the majority logic combination of the elementary codes, the correlation means (27, 27 a, 27 b, C) receive, on the one hand, the coded signal and, on the other hand, each of the elementary codes generated by the elementary generators of the receiver, and the control circuit (26, 26 ') of the elementary generators of the receiver (20) comprises wedging means acting in response to signals (that, Tb, Tc) provided by the correlation means (27; 27a, 27b, 27c) for wedging each of these elementary generators
independently of others.
  6 Device according to claim 5, characterized in that the correlation means comprise: a single correlator circuit (17) and switching means (28a, 28b, 28c) which are arranged between the elementary generators (22); , 23, 24) of the receiver and this correlator and which are controlled by signals
  (ca, cb, cc) provided by the control circuit (26).
  7 Apparatus according to claim 5, characterized in that the correlation means comprise a plurality of correlator circuits (27a, 27b, 27c) in number equal to that of the elementary generators (22, 23, -24) and receiving each, on the one hand, the coded signal (SC) and,
  on the other hand, a particular elementary code (a, b, c).
FR8312043A 1983-07-21 1983-07-21 Method and device for encoding and decoding broadband transmission Withdrawn FR2549663A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR8312043A FR2549663A1 (en) 1983-07-21 1983-07-21 Method and device for encoding and decoding broadband transmission

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
FR8312043A FR2549663A1 (en) 1983-07-21 1983-07-21 Method and device for encoding and decoding broadband transmission
US06/629,510 US4606039A (en) 1983-07-21 1984-07-10 Spread spectrum coding method and apparatus
JP59148490A JPH0522420B2 (en) 1983-07-21 1984-07-17
DE19843469120 DE3469120D1 (en) 1983-07-21 1984-07-18 Apparatus for coding and decoding a broad-band transmission
EP19840401504 EP0133107B1 (en) 1983-07-21 1984-07-18 Apparatus for coding and decoding a broad-band transmission

Publications (1)

Publication Number Publication Date
FR2549663A1 true FR2549663A1 (en) 1985-01-25

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EP (1) EP0133107B1 (en)
JP (1) JPH0522420B2 (en)
DE (1) DE3469120D1 (en)
FR (1) FR2549663A1 (en)

Families Citing this family (74)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0208425A3 (en) * 1985-06-13 1988-01-13 Devon County Council Television sub-carrier transmission
FR2589587B1 (en) * 1985-10-30 1988-02-05 Inst Francais Du Petrole Process for marine seismic prospecting using vibratory signal code and device for its implementation
DE3601576A1 (en) * 1986-01-21 1987-07-23 Standard Elektrik Lorenz Ag Receiver for spread spectrum signals
GB8621875D0 (en) * 1986-09-11 1986-11-05 Emi Plc Thorn Signal receiver
FR2606232B1 (en) * 1986-10-31 1988-12-02 Neiman Sa high security encoding method evolutionary and launching device OUT SAID METHOD
US4759034A (en) * 1986-12-02 1988-07-19 General Research Of Electronics, Inc. Multi-step spread spectrum communication apparatus
FR2612716B1 (en) * 1987-03-19 1989-05-19 Snecma Method and apparatus for encoding and decoding a wide emission has said band spread spectrum
US4776012A (en) * 1987-04-17 1988-10-04 Unisys Corporation Method of jumping composite PN codes
US5022047A (en) * 1989-08-07 1991-06-04 Omnipoint Data Corporation Spread spectrum correlator
US5499265A (en) * 1989-08-07 1996-03-12 Omnipoint Data Company, Incorporated Spread spectrum correlator
US5016255A (en) * 1989-08-07 1991-05-14 Omnipoint Data Company, Incorporated Asymmetric spread spectrum correlator
US5166952A (en) * 1990-05-24 1992-11-24 Cylink Corporation Method and apparatus for the reception and demodulation of spread spectrum radio signals
US5253268A (en) * 1990-05-24 1993-10-12 Cylink Corporation Method and apparatus for the correlation of sample bits of spread spectrum radio signals
US5157686A (en) * 1990-05-24 1992-10-20 Cylink Corporation Method and apparatus for the modulation of spread spectrum radio signals
US6693951B1 (en) 1990-06-25 2004-02-17 Qualcomm Incorporated System and method for generating signal waveforms in a CDMA cellular telephone system
US5103459B1 (en) * 1990-06-25 1999-07-06 Qualcomm Inc System and method for generating signal waveforms in a cdma cellular telephone system
WO1992002094A1 (en) * 1990-07-23 1992-02-06 Omnipoint Corporation Sawc phase-detection method and apparatus
US5081642A (en) * 1990-08-06 1992-01-14 Omnipoint Data Company, Incorporated Reciprocal saw correlator method and apparatus
WO1992007434A1 (en) * 1990-10-23 1992-04-30 Omnipoint Corporation Method and apparatus for establishing spread spectrum communications
US6873643B2 (en) * 1990-11-16 2005-03-29 Interdigital Technology Corporation Spread spectrum adaptive power control communications system and method
US5535238A (en) 1990-11-16 1996-07-09 Interdigital Technology Corporation Spread spectrum adaptive power control communications system and method
US5299226A (en) * 1990-11-16 1994-03-29 Interdigital Technology Corporation Adaptive power control for a spread spectrum communications system and method
US5263045A (en) * 1990-12-05 1993-11-16 Interdigital Technology Corporation Spread spectrum conference call system and method
US5506864A (en) 1990-12-05 1996-04-09 Interdigital Technology Corporation CDMA communications and geolocation system and method
US5703874A (en) * 1990-12-05 1997-12-30 Interdigital Technology Corporation Broadband CDMA overlay system and method
US7020125B2 (en) * 1990-12-05 2006-03-28 Interdigital Technology Corporation Broadband CDMA overlay system and method
US5351269A (en) * 1990-12-05 1994-09-27 Scs Mobilecom, Inc. Overlaying spread spectrum CDMA personal communications system
US5274665A (en) * 1990-12-14 1993-12-28 Interdigital Technology Corporation Polyopoly overlapping spread spectrum communication system and method
US5228056A (en) * 1990-12-14 1993-07-13 Interdigital Technology Corporation Synchronous spread-spectrum communications system and method
US5402413A (en) * 1991-04-08 1995-03-28 Omnipoint Corporation Three-cell wireless communication system
US5228053A (en) * 1991-05-15 1993-07-13 Interdigital Technology Corporation Spread spectrum cellular overlay CDMA communications system
US5161168A (en) * 1991-05-15 1992-11-03 Scs Mobilecom, Inc. Spread spectrum CDMA communications system microwave overlay
US5166951A (en) * 1991-05-15 1992-11-24 Scs Mobilecom, Inc. High capacity spread spectrum channel
USRE38627E1 (en) * 1991-05-15 2004-10-19 Interdigital Technology Corp. High capacity spread spectrum channel
US5185762A (en) * 1991-05-15 1993-02-09 Scs Mobilecom, Inc. Spread spectrum microwave overlay with notch filter
US5235615A (en) * 1991-05-22 1993-08-10 Cylink Corporation Spread spectrum method
US5164958A (en) * 1991-05-22 1992-11-17 Cylink Corporation Spread spectrum cellular handoff method
US5285469A (en) * 1991-06-03 1994-02-08 Omnipoint Data Corporation Spread spectrum wireless telephone system
US5345467A (en) * 1991-07-10 1994-09-06 Interdigital Technology Corp. CDMA cellular hand-off apparatus and method
US5210770A (en) * 1991-09-27 1993-05-11 Lockheed Missiles & Space Company, Inc. Multiple-signal spread-spectrum transceiver
US5267271A (en) * 1991-09-27 1993-11-30 Lockheed Missiles & Space Company, Inc. Signal analysis technique for determining a subject of binary sequences most likely to have been transmitted in a multi-node communication network
DE69232442T2 (en) * 1991-12-16 2002-08-22 Xircom Wireless Inc Spread spectrum data publication system
US5355389A (en) * 1993-01-13 1994-10-11 Omnipoint Corporation Reciprocal mode saw correlator method and apparatus
US5420883A (en) * 1993-05-17 1995-05-30 Hughes Aircraft Company Train location and control using spread spectrum radio communications
JPH06350562A (en) * 1993-06-08 1994-12-22 Ricoh Co Ltd Spread spectrum communication system
WO1995012945A1 (en) * 1993-11-01 1995-05-11 Omnipoint Corporation Despreading/demodulating direct sequence spread spectrum signals
US5692007A (en) * 1994-09-09 1997-11-25 Omnipoint Corporation Method and apparatus for differential phase encoding and decoding in spread-spectrum communication systems with continuous-phase modulation
US5627856A (en) * 1994-09-09 1997-05-06 Omnipoint Corporation Method and apparatus for receiving and despreading a continuous phase-modulated spread spectrum signal using self-synchronizing correlators
US5754584A (en) * 1994-09-09 1998-05-19 Omnipoint Corporation Non-coherent spread-spectrum continuous-phase modulation communication system
US5881100A (en) * 1994-09-09 1999-03-09 Omnipoint Corporation Method and apparatus for coherent correlation of a spread spectrum signal
US5659574A (en) * 1994-09-09 1997-08-19 Omnipoint Corporation Multi-bit correlation of continuous phase modulated signals
US5832028A (en) * 1994-09-09 1998-11-03 Omnipoint Corporation Method and apparatus for coherent serial correlation of a spread spectrum signal
US5757847A (en) * 1994-09-09 1998-05-26 Omnipoint Corporation Method and apparatus for decoding a phase encoded signal
US5610940A (en) * 1994-09-09 1997-03-11 Omnipoint Corporation Method and apparatus for noncoherent reception and correlation of a continous phase modulated signal
US5953370A (en) * 1994-09-09 1999-09-14 Omnipoint Corporation Apparatus for receiving and correlating a spread spectrum signal
US5680414A (en) * 1994-09-09 1997-10-21 Omnipoint Corporation Synchronization apparatus and method for spread spectrum receiver
US5963586A (en) * 1994-09-09 1999-10-05 Omnipoint Corporation Method and apparatus for parallel noncoherent correlation of a spread spectrum signal
US5856998A (en) * 1994-09-09 1999-01-05 Omnipoint Corporation Method and apparatus for correlating a continuous phase modulated spread spectrum signal
US5754585A (en) * 1994-09-09 1998-05-19 Omnipoint Corporation Method and apparatus for serial noncoherent correlation of a spread spectrum signal
US5629956A (en) * 1994-09-09 1997-05-13 Omnipoint Corporation Method and apparatus for reception and noncoherent serial correlation of a continuous phase modulated signal
US5648982A (en) * 1994-09-09 1997-07-15 Omnipoint Corporation Spread spectrum transmitter
US5592506A (en) * 1994-10-17 1997-01-07 Cylink Corporation MSK spread-spectrum receiver which allows CDMA operations
US5742583A (en) 1994-11-03 1998-04-21 Omnipoint Corporation Antenna diversity techniques
US5548253A (en) * 1995-04-17 1996-08-20 Omnipoint Corporation Spectrally efficient quadrature amplitude modulator
US5832022A (en) * 1995-06-02 1998-11-03 Omnipoint Corporation Method and apparatus for controlling the modulation index of continuous phase modulated (CPM) signals
US6356607B1 (en) 1995-06-05 2002-03-12 Omnipoint Corporation Preamble code structure and detection method and apparatus
US5745484A (en) * 1995-06-05 1998-04-28 Omnipoint Corporation Efficient communication system using time division multiplexing and timing adjustment control
US6014445A (en) * 1995-10-23 2000-01-11 Kabushiki Kaisha Toshiba Enciphering/deciphering apparatus and method incorporating random variable and keystream generation
US6141373A (en) * 1996-11-15 2000-10-31 Omnipoint Corporation Preamble code structure and detection method and apparatus
US6282228B1 (en) 1997-03-20 2001-08-28 Xircom, Inc. Spread spectrum codes for use in communication
US6324209B1 (en) * 2000-02-28 2001-11-27 Golden Bridge Technology Inc. Multi-channel spread spectrum system
US6956891B2 (en) * 2000-11-15 2005-10-18 Go-Cdma Limited Method and apparatus for non-linear code-division multiple access technology
RU2321400C2 (en) * 2001-03-14 2008-04-10 Бристол-Маерс Сквибб Компани Epotilone analogue composition in combination with chemotherapeutic agents for cancer treatment
EP1427116B1 (en) * 2002-12-04 2018-03-28 Nippon Telegraph And Telephone Corporation Spread-spectrum demodulator

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1549067A1 (en) * 1967-12-18 1971-01-28 Siemens Ag A method of generating binary numeral series
GB2111732A (en) * 1981-12-11 1983-07-06 Racal Res Ltd Signal processing arrangements

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2124320C1 (en) * 1971-05-17 1978-04-27 Siemens Ag, 1000 Berlin Und 8000 Muenchen
US4308617A (en) * 1977-11-07 1981-12-29 The Bendix Corporation Noiselike amplitude and phase modulation coding for spread spectrum transmissions
US4341925A (en) * 1978-04-28 1982-07-27 Nasa Random digital encryption secure communication system
JPS55120248A (en) * 1979-03-08 1980-09-16 Nippon Telegr & Teleph Corp <Ntt> Sound signal/control signal simultaneous transmission system
US4450321A (en) * 1981-12-08 1984-05-22 Quigley William D Circuit for producing noise generation for sound masking

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1549067A1 (en) * 1967-12-18 1971-01-28 Siemens Ag A method of generating binary numeral series
GB2111732A (en) * 1981-12-11 1983-07-06 Racal Res Ltd Signal processing arrangements

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
IEE PROCEEDINGS-F, vol. 128, no. 5, octobre 1981, Old Woking, Surrey (GB) *
R.C. DIXON:"Spread spectrum systems", 1976, pages 13-191, John Wiley & Sons, New York (US) *

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US4606039A (en) 1986-08-12
EP0133107B1 (en) 1988-01-27
JPS6051355A (en) 1985-03-22
EP0133107A1 (en) 1985-02-13
DE3469120D1 (en) 1988-03-03
JPH0522420B2 (en) 1993-03-29

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